中文摘要：

研究了由脂肪酸类表面活性剂与脂肪烷烃按一定比例复配而成的复合型添加剂对铝酸钠溶液二段法分解过程及最终产品氧化铝性能的影响及其作用机理。结果表明，当添加量为60×10^-6g·L^-1时，添加剂能够有效强化铝酸钠种分过程、改善分解产物质量，使溶液分解率提高大于2％；氢氧化铝颗粒小于45μm的质量分数降低约7％；氧化铝颗粒小于45μm的质量分数降低约6．7％。晶体形貌表明，添加剂的加入有效促进了氢氧化铝颗粒的附聚、长大过程，颗粒多呈球状，结晶比较完善。

英文摘要：

The effect of an additive prepared from fatty acid surface active agent and heneicosane on twostage seed precipitation process and Al2O3 production was studied. The results showed that the additive, with concentration of 60）K 10^-6 g· L^-1, enhanced remarkably the precipitation process and improved the quality of Al（OH）3 and Al2O3. The precipitation rate of sodium aluminate solution increased by 2%, and the percentage of 〈45μm particles of Al（OH）3 and Al2O3 reduced by about 7% and 6.7%, respectively by adding the additive. The SEM photographs indicated that the additive could accelerate growth, agglomeration of Al（OH）3 particles and the Al（OH）3 particles were in the shape of globular crystals. The mechanism of additive effect was also studied.